mk: link the whole cfgfile library

mk: link the whole cfgfile library

MRVL net pmd needs rte_cfgfile to parse QoS configuration file thus
librte_pmd_mrvl.a contains undefined symbols from librte_cfgfile.a.

As a result linking applications under app/ directory will fail
because librte_cfgfile.a comes before librte_pmd_mrvl.a during
the linking stage.

Linking the whole librte_cfgfile.a solves the issue.

Signed-off-by: Jacek Siuda <jck@semihalf.com>
Signed-off-by: Tomasz Duszynski <tdu@semihalf.com>